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Ballistics
NIJ Standards for Ballistic Resistant Protective Materials
This standard is applicable to all ballistic resistant materials (armor) intended to provide protection against gunfire, with the exception of police body armor and ballistic helmets, which are the topic of individual NIJ performance standards. Many different types of armor are now available that range in ballistic resistance from those designed to protect against small-caliber handguns to those designed to protect against high-powered rifles. Ballistic resistant materials are used to fabricate portable ballistic shields, such as a ballistic clipboard for use by a police officer; to provide ballistic protection for fixed structures such as critical control rooms or guard stations; and to provide ballistic protection for the occupants of vehicles. The ballistic resistant materials used to fabricate armor include metals, ceramics, transparent glazing, fabric, and fabric-reinforced plastics; they are used separately or in combination, depending upon the intended threat protection.
The ballistic threat posed by a bullet depends, among other things, on its composition, shape, caliber, mass, and impact velocity. Because of the wide variety of cartridges available in a given caliber, and because of the existence of hand loads, armors that will defeat a standard test round may not defeat other loadings in the same caliber. For example, an armor that prevents penetration by a 357 Magnum test round may or may not defeat a 357 Magnum round with a higher velocity. Similarly, for identical striking velocities, nondeforming or armor-piercing rounds pose a significantly greater penetration threat than an equivalent lead core round of the same caliber. The test ammunitions specified in this standard represent common threats to the law enforcement community.
Definitions
Angle of Incidence
The angle between the line of flight of the bullet and the perpendicular to the plane tangent to the point of impact (see fig. 1). Also known as angle of obliquity.
Fair Hit
A hit that impacts the ballistic resistant protective material at an angle of incidence no greater than 5°, and is at least 5 cm (2 in) from a prior hit or the edge of the test specimen and at an acceptable velocity as defined in this standard. A bullet that impacts too close to the edge or a prior hit and/or at too high a velocity, but does not penetrate, shall be considered a fair hit for the determination of nonpenetration.
Full Metal Jacketed (FMJ) Bullet
A bullet made of lead completely covered, except for the base, with copper alloy (approximately 90 copper-10 zinc).
Jacketed Soft Point (JSP) Bullet
A bullet made of lead completely covered, except for the point, with copper alloy (approximately 90 copper-10 zinc).
Lead Bullet
A bullet made of lead alloyed with hardening agents
Penetration
Perforation of a witness plate by any part of the test specimen or test bullet, as determined by passage of light when held up to a 60-W light bulb.
Strike Face
The surface of a ballistic resistant protective material designated by the manufacturer as the surface that should be exposed to (face) the weapon threat.
Semiwadcutter
A bullet shape characterized by a flat nose and a tapered section leading to a cylindrical bullet body with a sharp break where the taper meets the body.
Witness Plate
A thin sheet of aluminum alloy placed behind a test specimen to determine the potential for an incapacitating injury.
Classifications
Ballistic resistant protective materials covered by this standard are classified into five types, by level of performance.
Type 1 (22 LR; 38 Special)
This armor protects against the following standard test rounds:
22 LR
22-caliber handgun with a 6 to 6.5in barrel. Bullets would be 22 Long Rifle High Velocity lead with nominal masses
of 2.6g and measured velocities of 320 ± 12m per second.
38 Special
38 special handgun with 6 to 6.5in barrel. Bullets would be 38 special round-nose lead, with nominal masses of
2.6g and measured velocities of 259 ± 15 m per second.
It also provides protection against lesser threats such as 12 gauge No. 4 lead shot and most handgun rounds in calibers 25 and 32.
Type II-A (Lower Velocity 357 Magnum; 9 mm)
This armor protects against the following standard test rounds:
Lower Velocity 357 Magnum
Weapon would be a 357 Magnum handgun with a 4 to 4.75 in barrel. Bullets would be 357 Magnum jacketed soft point with nominal masses of 10.2g and measured velocities of 381 ± 15 m per second
Lower Velocity 9mm
Weapon would be a 9mm handgun with a 4 to 4.75 in barrel. Bullets would be 9mm full metal jacketed with nominal masses of 8.0g and measured velocities of 332 ± 12 m per second
It also provides protection against lesser threats such as 12 gauge 00 buckshot, 45 Auto., 38 Special ± P and other factory loads in caliber 357 Magnum and 9 mm, as well as the threats mentioned in Type I.
Type II (Higher Velocity 357 Magnum; 9 mm)
This armor protects against the following standard test rounds:
Higher Velocity 357 Magnum
Weapon would be a 357 Magnum handgun with a 6 to 6.50 in barrel. Bullets would be 357 Magnum jacketed soft point with nominal masses of 10.2g and measured velocities of 425 ± 15 m per second
Lower Velocity 9mm
Weapon would be a 9mm handgun with a 4 to 4.75 in barrel. Bullets would be 9mm full metal jacketed with nominal masses of 8.0g and measured velocities of 358 ± 12 m per second
It also provides protection against most other factory loads in caliber 357 Magnum and 9 mm, as well as threats mentioned in Type I and Type II-A.
Type III-A (44 Magnum; Submachine Gun 9 mm)
This armor protects against the following standard test rounds:
44 Magnum
Weapon would be a 44 Magnum handgun with a 5.5 to 6.25 in barrel. Bullets would be 44 Magnum lead semiwadcutter with gas checks, and nominal masses of 15.55g and measured velocities of 426 ± 15 m per second
Submachine Gun (SMG) 9mm
Weapon would be a 9mm SMG with a 9.5 to 10.25 in barrel. Bullets would be 9mm full metal jacketed with nominal masses of 8.0g and measured velocities of 426 ± 15 m per second
It also provides protection against most handgun threats as well as the threats mentioned in Type I through Type II.
Type III (High-Powered Rifle)
This armor protects against a standard test round of a rifle chambered for 7.62-mm (308 Winchester) ammunition with a barrel length of 22in. The bullets would be 7.62 mm full metal jacketed (US military designation M80) with nominal masses of 9.7g and measured velocities of 838 ± 15 m per second. It also provides protection against most lesser threats such as 223 Remington (5.56 mm FMJ), 30 Carbine FMJ, and 12 gauge rifle slug, as well as the threats mentioned in Type I through Type III-A.
Type IV (Armor-Piercing Rifle)
This armor protects against the standard test round of a rifle chambered for 7.62-mm (308 Winchester) ammunition with a barrel length of 22in. The bullets would be 30 caliber armor piercing (US military designation APM2) with nominal masses of 10.8g and measured velocities of 868 ± 15 m per second. It also provides at least single hit protection against the threats mentioned in sections Type I through Type III.
Special Type
A purchaser having a special requirement for a level of protection other than one of the above standards should specify the exact test rounds to be used, and indicate that this standard shall govern in all other respects.
How does NIJ compare to other Ballistic Armor Standards
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